24 x 156 x 5 TRS-80 Graphics

The TRS-80 Model 3 has just enough CPU time per scan line to change 12
graphics characters. Since each character is 2 pixels wide that gives full
control over 24 pixels. After a bit of experimenting I figured that about
5 levels of grayscale was reasonable by alternating different subsets of 12
frames. The code could do a full 24 x 192 display but its pretty memory
intensive. The 12 frames will only fit into 48 KB if the vertical resolution
is limited to 156.

The following image flips simulate what you'd see on a real TRS-80. The
emulator does a better job, of course.

Standing back from your display makes the image look a bit better. Do
you recognize the celebrity?